Not sure if intended or not, (and by extent, I’m not sure if this is a suggestion or a bug report, but what can you do…) but you can’t repair chitin stuff. At all.
As a Morrowind player, I can assure you that I love my Chitin based armor (Screw yo Daedric) and I’m quite happy to have it in this game. However, having no way to reinforce/repair it, even with chitin chunks, is annoying, since ALL my other clothes are reinforced. Even that radiation badge I picked up somewhere. (The deputy badge isn’t, though. If it isn’t made of metal, kevlar, plastic, cloth, wool, fur, or leather, then what IS it made of? Are the police force harvesting giant spiders for their gold stars too?) Simply put, I’d like the ability to repair chitin stuff with chitin chunks, and probably a soldering iron, since I don’t think a needle can pierce exoskeleton that well.
TL;DR Lemme repair/reinforce my chitinous chitin with chitinous chunks of chitin and a soldering iron. And the same with the deputy star and scrap metal (or plastic chunks, depending on how bad the Law Enforcement budget was), since it’s annoying having that one single piece of clothing that isn’t reinforced, even if it’s pointless since it’s effectively unbreakable anyway.